1. Field of Invention
This invention relates to a lighting system, specifically to control system and circuit for a light emitting diode (LED) lighting system operated under a constant temperature.
2. Description of Prior Art
In recent years, concerns have been raised that high demand for electricity taxing the capacity of existing electricity generating plants. Furthermore, concerns regarding the availability and environmental safety of fossil and nuclear fuel are being raised. As a result of the above factors, the price of electricity has been on a path of steady increasing. It has become increasingly common to seek low power consumption electrical appliances. LED has increasingly been employed as light sources for homes and for street lights.
LED has long operating lifetimes in relation to conventional incandescent and fluorescent light sources. Despite their advantages and increased usages, LED at an elevated temperature is susceptible to degradation of performance and/or lifetime. For example, a LED operated at an elevated temperature at 80C or above can experience significant degradation.
Therefore, there exists a need to control the operating temperature of LED lighting system in order to maintain optimized performances and to achieve a desired long lifetime.